Heart Septal Defect Occlusion Devices With Adjustable Length Tether Adapting To The Unique Anatomy Of The Patient

ABSTRACT

The present invention relates to heart septal defect occlusion devices with adjustable length tether which can adapt the interseptal length of the device to the unique anatomy of the patient. The right disc as recited in the present invention is made from a double-deck metal mesh with contraction function, and the left disc is made from at least two skeletons covered by membranes. The two discs are active linked together. Because the connection of the two discs has gimbal function and the distance between the two discs may expand and contract suitably, the device can adapt to the unique anatomy of the patient. Therefore the two discs may attach to the heart valves closely and increase its closing ability. Furthermore it can reduce the thrombus and operate more easily.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of a Chinese patent application No.20051 0032924.0 (CN), filed on Jan. 28, 2005.

TECHNICAL FIELD

The present invention relates to an occlusion device for treating ofcongenital heart disease, such as patent foramen ovale (PFO), atrialseptal defect (ASD), patent ductus arteriosus (PDA) or ventricularseptal defect (VSD) etc.

BACKGROUND OF THE INVENTION

Congenital heart diseases include patent foramen ovale (PFO), atrialseptal defect (ASD), patent ductus arteriosus (PDA) and ventricularseptal defect (VSD) etc. Thereinto, PFO and ASD are open in the wallbetween the right atrium and left atrium of the heart. So it creates thepossibility that the blood could pass from the right atrium to the leftatrium. But the defect size of PFO is usually smaller than that of ASDand the defect will not vertical extend to the valve wall, i.e. leftatrial valve defect is not concentric with that of right atrium. Oncethe occluder placed, it will prevent the thrombus entering into the leftatrium effectively. Furthermore, the atrial septal defect (ASD) isbigger usually and needs to repair. Currently there are many typesendocardiac occlusion devices for treating of congenital heart diseases.These occluders will be delivered to the desired location bycorresponding catheter.

Mechanical occlusion devices for treating of congenital heart diseaseshave been proposed in the past, some of which are disclosed in Frankeret al., Chinese patent application No. 97194488.1; Franker et al.,Chinese patent application No. 98808876.2; and Michael et al., Chinesepatent application No. 98813470.5. This kind of device includes asupport mesh with contractibility and biocompatible materials, and thebiocompatible materials are connected to the circumference of thesupport mesh. The support mesh, which is put into the catheter firstly,is delivered to the desired location, and then is deployed to close theseptal defect. This kind of device is easily to withdraw and hasexcellent centricity. However, the left disc of this device is directlytouch blood, so that it can form thrombus and release harmful metallicelements more easily. Moreover, because the two discs are a whole, itcannot automatic adjust the angle to adapt to the unique anatomy of thepatient. Meanwhile, because the left disc could not deploy completelyafter it leads to operate more complicated. Additional, under theexisting technique and the operation method, it is very difficult todetermine the size and shape of the septal defect precisely, as well thelimit of waist size, it will bring many difficulties to physicians, suchas selection error etc. If select the bigger one, the occluder will formcucurbit shape, and result in the closing effect is not perfect.

Accordingly, it would be advantageous to provide a reliable device whichcan automatic adjust the angle to adapt to the unique anatomy of thepatient.

SUMMARY OF THE INVENTION

The present invention provides a reliable occlusion device withadjustable length tether which can adapt the interseptal length of thedevice to the unique anatomy of the patient. The two discs can attach tothe defect valves closely, so it can increases the closing ability.Moreover, it can also reduce the thrombus because of its left disc whichcovered with membranes and operate more easily.

The present invention provides a occlusion device which the right discis made from a double-deck wire mesh with contraction function, and theleft disc is made from at least two skeletons which covered withmembranes, and the two discs are active linked together by the skeletonsdrilling through the mesh of the right disc.

The middle segment of each skeleton is U shape, and the depths of the Utrough are different. So the skeleton can form a plane after beinglinked together. Then covered with membranes to form disc shape.

The left disc is made from several radial-extending skeletons by heattreatment, and covered with membranes, and the center of each skeletonis radial extending after overlapping together.

The two ends of each skeleton which is sphere shape are wrapped by themembranes, and the ends of the right disc are fixed by a tip or a joint,then the right disc undergoes heat treatment. Then the skeletons drillthrough the mesh near the tip and are overlapped together. The membranesare made from biocompatible materials.

Furthermore, because the connection of the two discs has gimbal functionand the distances between the two discs may expand and contractsuitably, the device can adapt the interseptal length between two discsfor the unique anatomy of the patient. Therefore, the two discs mayattach to the heart valves closely and increase its closing ability.Moreover, it can reduce the thrombus as well as harmful elements becauseof its left disc being covered with membranes. Additional, the device,which is fission structure, i.e. its two discs could deploy completely,is easy to operate and increase the closing reliability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a disc which is constructed byskeletons in according with the invention.

FIG. 2 is a side view of the right disc in according with the invention.

FIG. 3 is a side view of the skeleton in according with the invention.

FIG. 4 is a side view of the occlusion device in according with theinvention.

FIG. 5 is an enlarged partial sectional view of part A as shown in FIG.4.

FIG. 6 is a front view of the occlusion device in according with theinvention.

FIG. 7 and FIG. 8 are a side view of another alternative skeletonrespectively.

FIG. 9 is a side view of the membrane, which used to cover the skeletonsin according with the invention.

FIG. 10 is a side view of the skeletons, which have been covered withmembranes shown in FIG. 9.

FIG. 11 is a schematic representation of a mould, which is used toheat-treat the skeletons.

FIG. 12 is a schematic representation of PFO occluder being releasedfrom delivery catheter.

FIG. 13 is a schematic representation of ASD occluder being releasedfrom delivery catheter.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a heart septal defect occlusion devicefor occluding an anatomical aperture, such as patent foramen ovaleoccluder in FIG. 4. The occluder comprises right disc 21 (i.e. metalmesh disc), tip 22, joint 23, left disc 1 which covered with membranesand membranes 100 as shown in FIG. 1 and FIG. 9.

In the present invention, PFO occluder will be selected as an example.The maximal character of the PFO occluder, which compared with those ofabove referring to patents, is that the left disc 1 comprises sixskeletons 11 which distribute evenly. And the six skeletons are linkedtogether in the center and form a radial-extending disc. It is certainlythat the left disc 1 may comprise at least two skeleton 11 as shown inFIG. 2, and skeleton 11 is made from nitinol wire with shape memory.FIG. 11 illustrates the mould which is used to heat treat skeletons 1,the mould includes upper-mould 201 ,middle-mould 202 and under-mould 203and the nitinol wire will be put into the rabbet of the middle-mould201. By heating the nitinol wire above a certain phase transitiontemperature, the crystal structure of the nitinol wire when in itsaustenitic phase can be set, and this will tend to “set” the shape ofthe device, i.e. it can keep it's shape of which it is fixed into themould. Except for an outside force, otherwise it can keep the “set”shape invariable even if cooled, and when the outside force iswithdrawn, it can resume its original shape. The middle segment of theskeleton 11 is U shape, and the depth of each U trough are different.Just because of these different depth U troughs, these skeletons canform a plane after being overlapped together. Then covered withmembranes to form the left disc1. The right disc 21 of PFO occluder usesmoulding components. Firstly, the suitable tubular metal mesh of PFOoccluder is formed by weave or laser carving, then the tubular metalmesh is inserted into the mould and undergoes heat treatment. And, weldthe tip 22 and joint 23 to the disc as shown in FIG. 2.

After the two ends of that being weld into spheres respectively, theskeleton 11 as shown in FIG. 3 is drilled through the right disc 21 andnear the tip 22, and then form a double-disc structure as shown in FIG.5. And as shown in FIG. 6, the skeleton 11 are distributed evenly.Accordingly, these skeletons 11 form a metal disc as shown in FIG. 4.

The two sides of the left disc 1 are covered with membranes 100 as shownin FIG. 9, and FIG. 10 illustrates the skeleton 11 are covered membranes100. The membranes are made from biocompatible materials. As describedabove, the spheres of each skeleton are wrapped in the biocompatiblematerials, so that it can prevent skeleton 11 from puncturing themembranes 100. And another membrane made by biocompatible material 24 isfilled into the right disc 21.

As described above, the overlapping point of left disc 1 drill throughright disc 21, and the connection between the two discs has gimbalfunction. Furthermore, the two discs have a trend of shrinking towardinner, and the occlusion device may swing randomly, i.e., the left disc1 and right disc 21 may be parallel or have an angle. Accordingly, thedevice can adapt to the unique anatomy in patient, and the two discs canattach to the defect closely. Additionally, alternative structure andassembly mode of the skeleton 11 are shown in FIG. 7 and FIG. 8.

The occlusion device as described above may be extended and put into thecatheter, and is delivered to the desired location, then is released.The taper waist of the device not only ensures its self-centricity butalso can reduce the probability of bad occlusion effect resulted fromselection error. Left disc, which comprises skeletons and membranes, candecrease metal surface areas, thrombus formation as well as harmelements. The two discs are both individual components, they can deploycompletely after releasing, and this can avoid forming cucurbit shapeand increase the reliability of occlusion.

FIG. 12 and FIG. 13 illustrate the deployment process of FPO occluderand ASD occluder during operation respectively. Moreover, the occluderhas excellent self-centricity due to its right disc 21 closes to theleft disc 1.

The present invention is also suitable for treating of PDA and VSD etc.The only difference, which compared with those of above other occluders,is the metal mesh of PDA occluder will not form a disc, but a “waist”.

Although the description above contains many specificities, these shouldnot be construed as limiting the scope of the invention but as merelyproviding illustrations of some of the presently preferred embodimentsof this invention. Thus the scope of the invention should be determinedby the appended claims and their legal equivalents, rather than by theexamples given.

1. A heart septal defect occlusion devices with adjustable length tetheradapting to the unique anatomy of the patient comprising a right discmade from a double-deck metal mesh with contraction function, a leftdisc made from at least two skeletons covered with a membrane, saidskeletons drilling through the mesh of said right disc to active linksaid right and left discs.
 2. The device as claimed by claim 1 whereinsaid the middle segment of each said skeleton is U shape, the depth ofthe U trough is different for said skeletons forming a plane after beinglinked together, said plane is covered with membranes.
 3. The device asclaimed by claim 2 wherein said left disc is made from several radialskeletons, and is covered with membranes for stopping blood flow.
 4. Thedevice as claimed by claim 3 wherein said skeletons are covered withmembranes on its both sides.
 5. The device as claimed by claim 4 whereinthe two ends of said skeleton are spherical, and are wrapped in saidmembranes.
 6. The device as claimed by claim 5 wherein the two spheresof said skeleton are wrapped by said membrane below.
 7. The device asclaimed by claim 1 wherein the ends of said right disc are fixed by aconnector, and then said right disc undergoes heat treatment to form adisc structure.
 8. The device as claimed by claim 1 wherein the ends ofsaid right disc are fixed by a tip or joint, said right disc undergoesheat treatment to form a disc structure.
 9. The device as claimed byclaim 8 wherein said skeletons drill through the metal mesh near the tipor joint.
 10. The device as claimed by claim 9 wherein said skeletonsoverlap each other by drilling through the metal mesh near the tip. 11.The device as claimed by claim 1 wherein said membranes are made bybiocompatible materials.
 12. The device as claimed by claim 1 whereinsaid skeletons are made by nitinol wire with shape memory.
 13. Thedevice as claimed by claim 1 wherein said right disc is active linkedwith said left disc.
 14. The device as claimed by claim 1 wherein saidleft and right discs have a trend of shrinking toward inner, they may beparallel or have an angle to possessing self-adjustment function forthose defects with different thickness and attaching to defect closely.